OK, let's crack this. We're given 670 and our task is to multiply it by 425. Essentially, we'll be adding 670 to itself 425 times.
Step 1: 0 + 670 = 670
Step 2: 670 + 670 = 1340
Step 3: 1340 + 670 = 2010
Step 4: 2010 + 670 = 2680
Step 5: 2680 + 670 = 3350
Step 6: 3350 + 670 = 4020
Step 7: 4020 + 670 = 4690
Step 8: 4690 + 670 = 5360
Step 9: 5360 + 670 = 6030
Step 10: 6030 + 670 = 6700
Step 11: 6700 + 670 = 7370
Step 12: 7370 + 670 = 8040
Step 13: 8040 + 670 = 8710
Step 14: 8710 + 670 = 9380
Step 15: 9380 + 670 = 10050
Step 16: 10050 + 670 = 10720
Step 17: 10720 + 670 = 11390
Step 18: 11390 + 670 = 12060
Step 19: 12060 + 670 = 12730
Step 20: 12730 + 670 = 13400
Step 21: 13400 + 670 = 14070
Step 22: 14070 + 670 = 14740
Step 23: 14740 + 670 = 15410
Step 24: 15410 + 670 = 16080
Step 25: 16080 + 670 = 16750
Step 26: 16750 + 670 = 17420
Step 27: 17420 + 670 = 18090
Step 28: 18090 + 670 = 18760
Step 29: 18760 + 670 = 19430
Step 30: 19430 + 670 = 20100
Step 31: 20100 + 670 = 20770
Step 32: 20770 + 670 = 21440
Step 33: 21440 + 670 = 22110
Step 34: 22110 + 670 = 22780
Step 35: 22780 + 670 = 23450
Step 36: 23450 + 670 = 24120
Step 37: 24120 + 670 = 24790
Step 38: 24790 + 670 = 25460
Step 39: 25460 + 670 = 26130
Step 40: 26130 + 670 = 26800
Step 41: 26800 + 670 = 27470
Step 42: 27470 + 670 = 28140
Step 43: 28140 + 670 = 28810
Step 44: 28810 + 670 = 29480
Step 45: 29480 + 670 = 30150
Step 46: 30150 + 670 = 30820
Step 47: 30820 + 670 = 31490
Step 48: 31490 + 670 = 32160
Step 49: 32160 + 670 = 32830
Step 50: 32830 + 670 = 33500
Step 51: 33500 + 670 = 34170
Step 52: 34170 + 670 = 34840
Step 53: 34840 + 670 = 35510
Step 54: 35510 + 670 = 36180
Step 55: 36180 + 670 = 36850
Step 56: 36850 + 670 = 37520
Step 57: 37520 + 670 = 38190
Step 58: 38190 + 670 = 38860
Step 59: 38860 + 670 = 39530
Step 60: 39530 + 670 = 40200
Step 61: 40200 + 670 = 40870
Step 62: 40870 + 670 = 41540
Step 63: 41540 + 670 = 42210
Step 64: 42210 + 670 = 42880
Step 65: 42880 + 670 = 43550
Step 66: 43550 + 670 = 44220
Step 67: 44220 + 670 = 44890
Step 68: 44890 + 670 = 45560
Step 69: 45560 + 670 = 46230
Step 70: 46230 + 670 = 46900
Step 71: 46900 + 670 = 47570
Step 72: 47570 + 670 = 48240
Step 73: 48240 + 670 = 48910
Step 74: 48910 + 670 = 49580
Step 75: 49580 + 670 = 50250
Step 76: 50250 + 670 = 50920
Step 77: 50920 + 670 = 51590
Step 78: 51590 + 670 = 52260
Step 79: 52260 + 670 = 52930
Step 80: 52930 + 670 = 53600
Step 81: 53600 + 670 = 54270
Step 82: 54270 + 670 = 54940
Step 83: 54940 + 670 = 55610
Step 84: 55610 + 670 = 56280
Step 85: 56280 + 670 = 56950
Step 86: 56950 + 670 = 57620
Step 87: 57620 + 670 = 58290
Step 88: 58290 + 670 = 58960
Step 89: 58960 + 670 = 59630
Step 90: 59630 + 670 = 60300
Step 91: 60300 + 670 = 60970
Step 92: 60970 + 670 = 61640
Step 93: 61640 + 670 = 62310
Step 94: 62310 + 670 = 62980
Step 95: 62980 + 670 = 63650
Step 96: 63650 + 670 = 64320
Step 97: 64320 + 670 = 64990
Step 98: 64990 + 670 = 65660
Step 99: 65660 + 670 = 66330
Step 100: 66330 + 670 = 67000
Step 101: 67000 + 670 = 67670
Step 102: 67670 + 670 = 68340
Step 103: 68340 + 670 = 69010
Step 104: 69010 + 670 = 69680
Step 105: 69680 + 670 = 70350
Step 106: 70350 + 670 = 71020
Step 107: 71020 + 670 = 71690
Step 108: 71690 + 670 = 72360
Step 109: 72360 + 670 = 73030
Step 110: 73030 + 670 = 73700
Step 111: 73700 + 670 = 74370
Step 112: 74370 + 670 = 75040
Step 113: 75040 + 670 = 75710
Step 114: 75710 + 670 = 76380
Step 115: 76380 + 670 = 77050
Step 116: 77050 + 670 = 77720
Step 117: 77720 + 670 = 78390
Step 118: 78390 + 670 = 79060
Step 119: 79060 + 670 = 79730
Step 120: 79730 + 670 = 80400
Step 121: 80400 + 670 = 81070
Step 122: 81070 + 670 = 81740
Step 123: 81740 + 670 = 82410
Step 124: 82410 + 670 = 83080
Step 125: 83080 + 670 = 83750
Step 126: 83750 + 670 = 84420
Step 127: 84420 + 670 = 85090
Step 128: 85090 + 670 = 85760
Step 129: 85760 + 670 = 86430
Step 130: 86430 + 670 = 87100
Step 131: 87100 + 670 = 87770
Step 132: 87770 + 670 = 88440
Step 133: 88440 + 670 = 89110
Step 134: 89110 + 670 = 89780
Step 135: 89780 + 670 = 90450
Step 136: 90450 + 670 = 91120
Step 137: 91120 + 670 = 91790
Step 138: 91790 + 670 = 92460
Step 139: 92460 + 670 = 93130
Step 140: 93130 + 670 = 93800
Step 141: 93800 + 670 = 94470
Step 142: 94470 + 670 = 95140
Step 143: 95140 + 670 = 95810
Step 144: 95810 + 670 = 96480
Step 145: 96480 + 670 = 97150
Step 146: 97150 + 670 = 97820
Step 147: 97820 + 670 = 98490
Step 148: 98490 + 670 = 99160
Step 149: 99160 + 670 = 99830
Step 150: 99830 + 670 = 100500
Step 151: 100500 + 670 = 101170
Step 152: 101170 + 670 = 101840
Step 153: 101840 + 670 = 102510
Step 154: 102510 + 670 = 103180
Step 155: 103180 + 670 = 103850
Step 156: 103850 + 670 = 104520
Step 157: 104520 + 670 = 105190
Step 158: 105190 + 670 = 105860
Step 159: 105860 + 670 = 106530
Step 160: 106530 + 670 = 107200
Step 161: 107200 + 670 = 107870
Step 162: 107870 + 670 = 108540
Step 163: 108540 + 670 = 109210
Step 164: 109210 + 670 = 109880
Step 165: 109880 + 670 = 110550
Step 166: 110550 + 670 = 111220
Step 167: 111220 + 670 = 111890
Step 168: 111890 + 670 = 112560
Step 169: 112560 + 670 = 113230
Step 170: 113230 + 670 = 113900
Step 171: 113900 + 670 = 114570
Step 172: 114570 + 670 = 115240
Step 173: 115240 + 670 = 115910
Step 174: 115910 + 670 = 116580
Step 175: 116580 + 670 = 117250
Step 176: 117250 + 670 = 117920
Step 177: 117920 + 670 = 118590
Step 178: 118590 + 670 = 119260
Step 179: 119260 + 670 = 119930
Step 180: 119930 + 670 = 120600
Step 181: 120600 + 670 = 121270
Step 182: 121270 + 670 = 121940
Step 183: 121940 + 670 = 122610
Step 184: 122610 + 670 = 123280
Step 185: 123280 + 670 = 123950
Step 186: 123950 + 670 = 124620
Step 187: 124620 + 670 = 125290
Step 188: 125290 + 670 = 125960
Step 189: 125960 + 670 = 126630
Step 190: 126630 + 670 = 127300
Step 191: 127300 + 670 = 127970
Step 192: 127970 + 670 = 128640
Step 193: 128640 + 670 = 129310
Step 194: 129310 + 670 = 129980
Step 195: 129980 + 670 = 130650
Step 196: 130650 + 670 = 131320
Step 197: 131320 + 670 = 131990
Step 198: 131990 + 670 = 132660
Step 199: 132660 + 670 = 133330
Step 200: 133330 + 670 = 134000
Step 201: 134000 + 670 = 134670
Step 202: 134670 + 670 = 135340
Step 203: 135340 + 670 = 136010
Step 204: 136010 + 670 = 136680
Step 205: 136680 + 670 = 137350
Step 206: 137350 + 670 = 138020
Step 207: 138020 + 670 = 138690
Step 208: 138690 + 670 = 139360
Step 209: 139360 + 670 = 140030
Step 210: 140030 + 670 = 140700
Step 211: 140700 + 670 = 141370
Step 212: 141370 + 670 = 142040
Step 213: 142040 + 670 = 142710
Step 214: 142710 + 670 = 143380
Step 215: 143380 + 670 = 144050
Step 216: 144050 + 670 = 144720
Step 217: 144720 + 670 = 145390
Step 218: 145390 + 670 = 146060
Step 219: 146060 + 670 = 146730
Step 220: 146730 + 670 = 147400
Step 221: 147400 + 670 = 148070
Step 222: 148070 + 670 = 148740
Step 223: 148740 + 670 = 149410
Step 224: 149410 + 670 = 150080
Step 225: 150080 + 670 = 150750
Step 226: 150750 + 670 = 151420
Step 227: 151420 + 670 = 152090
Step 228: 152090 + 670 = 152760
Step 229: 152760 + 670 = 153430
Step 230: 153430 + 670 = 154100
Step 231: 154100 + 670 = 154770
Step 232: 154770 + 670 = 155440
Step 233: 155440 + 670 = 156110
Step 234: 156110 + 670 = 156780
Step 235: 156780 + 670 = 157450
Step 236: 157450 + 670 = 158120
Step 237: 158120 + 670 = 158790
Step 238: 158790 + 670 = 159460
Step 239: 159460 + 670 = 160130
Step 240: 160130 + 670 = 160800
Step 241: 160800 + 670 = 161470
Step 242: 161470 + 670 = 162140
Step 243: 162140 + 670 = 162810
Step 244: 162810 + 670 = 163480
Step 245: 163480 + 670 = 164150
Step 246: 164150 + 670 = 164820
Step 247: 164820 + 670 = 165490
Step 248: 165490 + 670 = 166160
Step 249: 166160 + 670 = 166830
Step 250: 166830 + 670 = 167500
Step 251: 167500 + 670 = 168170
Step 252: 168170 + 670 = 168840
Step 253: 168840 + 670 = 169510
Step 254: 169510 + 670 = 170180
Step 255: 170180 + 670 = 170850
Step 256: 170850 + 670 = 171520
Step 257: 171520 + 670 = 172190
Step 258: 172190 + 670 = 172860
Step 259: 172860 + 670 = 173530
Step 260: 173530 + 670 = 174200
Step 261: 174200 + 670 = 174870
Step 262: 174870 + 670 = 175540
Step 263: 175540 + 670 = 176210
Step 264: 176210 + 670 = 176880
Step 265: 176880 + 670 = 177550
Step 266: 177550 + 670 = 178220
Step 267: 178220 + 670 = 178890
Step 268: 178890 + 670 = 179560
Step 269: 179560 + 670 = 180230
Step 270: 180230 + 670 = 180900
Step 271: 180900 + 670 = 181570
Step 272: 181570 + 670 = 182240
Step 273: 182240 + 670 = 182910
Step 274: 182910 + 670 = 183580
Step 275: 183580 + 670 = 184250
Step 276: 184250 + 670 = 184920
Step 277: 184920 + 670 = 185590
Step 278: 185590 + 670 = 186260
Step 279: 186260 + 670 = 186930
Step 280: 186930 + 670 = 187600
Step 281: 187600 + 670 = 188270
Step 282: 188270 + 670 = 188940
Step 283: 188940 + 670 = 189610
Step 284: 189610 + 670 = 190280
Step 285: 190280 + 670 = 190950
Step 286: 190950 + 670 = 191620
Step 287: 191620 + 670 = 192290
Step 288: 192290 + 670 = 192960
Step 289: 192960 + 670 = 193630
Step 290: 193630 + 670 = 194300
Step 291: 194300 + 670 = 194970
Step 292: 194970 + 670 = 195640
Step 293: 195640 + 670 = 196310
Step 294: 196310 + 670 = 196980
Step 295: 196980 + 670 = 197650
Step 296: 197650 + 670 = 198320
Step 297: 198320 + 670 = 198990
Step 298: 198990 + 670 = 199660
Step 299: 199660 + 670 = 200330
Step 300: 200330 + 670 = 201000
Step 301: 201000 + 670 = 201670
Step 302: 201670 + 670 = 202340
Step 303: 202340 + 670 = 203010
Step 304: 203010 + 670 = 203680
Step 305: 203680 + 670 = 204350
Step 306: 204350 + 670 = 205020
Step 307: 205020 + 670 = 205690
Step 308: 205690 + 670 = 206360
Step 309: 206360 + 670 = 207030
Step 310: 207030 + 670 = 207700
Step 311: 207700 + 670 = 208370
Step 312: 208370 + 670 = 209040
Step 313: 209040 + 670 = 209710
Step 314: 209710 + 670 = 210380
Step 315: 210380 + 670 = 211050
Step 316: 211050 + 670 = 211720
Step 317: 211720 + 670 = 212390
Step 318: 212390 + 670 = 213060
Step 319: 213060 + 670 = 213730
Step 320: 213730 + 670 = 214400
Step 321: 214400 + 670 = 215070
Step 322: 215070 + 670 = 215740
Step 323: 215740 + 670 = 216410
Step 324: 216410 + 670 = 217080
Step 325: 217080 + 670 = 217750
Step 326: 217750 + 670 = 218420
Step 327: 218420 + 670 = 219090
Step 328: 219090 + 670 = 219760
Step 329: 219760 + 670 = 220430
Step 330: 220430 + 670 = 221100
Step 331: 221100 + 670 = 221770
Step 332: 221770 + 670 = 222440
Step 333: 222440 + 670 = 223110
Step 334: 223110 + 670 = 223780
Step 335: 223780 + 670 = 224450
Step 336: 224450 + 670 = 225120
Step 337: 225120 + 670 = 225790
Step 338: 225790 + 670 = 226460
Step 339: 226460 + 670 = 227130
Step 340: 227130 + 670 = 227800
Step 341: 227800 + 670 = 228470
Step 342: 228470 + 670 = 229140
Step 343: 229140 + 670 = 229810
Step 344: 229810 + 670 = 230480
Step 345: 230480 + 670 = 231150
Step 346: 231150 + 670 = 231820
Step 347: 231820 + 670 = 232490
Step 348: 232490 + 670 = 233160
Step 349: 233160 + 670 = 233830
Step 350: 233830 + 670 = 234500
Step 351: 234500 + 670 = 235170
Step 352: 235170 + 670 = 235840
Step 353: 235840 + 670 = 236510
Step 354: 236510 + 670 = 237180
Step 355: 237180 + 670 = 237850
Step 356: 237850 + 670 = 238520
Step 357: 238520 + 670 = 239190
Step 358: 239190 + 670 = 239860
Step 359: 239860 + 670 = 240530
Step 360: 240530 + 670 = 241200
Step 361: 241200 + 670 = 241870
Step 362: 241870 + 670 = 242540
Step 363: 242540 + 670 = 243210
Step 364: 243210 + 670 = 243880
Step 365: 243880 + 670 = 244550
Step 366: 244550 + 670 = 245220
Step 367: 245220 + 670 = 245890
Step 368: 245890 + 670 = 246560
Step 369: 246560 + 670 = 247230
Step 370: 247230 + 670 = 247900
Step 371: 247900 + 670 = 248570
Step 372: 248570 + 670 = 249240
Step 373: 249240 + 670 = 249910
Step 374: 249910 + 670 = 250580
Step 375: 250580 + 670 = 251250
Step 376: 251250 + 670 = 251920
Step 377: 251920 + 670 = 252590
Step 378: 252590 + 670 = 253260
Step 379: 253260 + 670 = 253930
Step 380: 253930 + 670 = 254600
Step 381: 254600 + 670 = 255270
Step 382: 255270 + 670 = 255940
Step 383: 255940 + 670 = 256610
Step 384: 256610 + 670 = 257280
Step 385: 257280 + 670 = 257950
Step 386: 257950 + 670 = 258620
Step 387: 258620 + 670 = 259290
Step 388: 259290 + 670 = 259960
Step 389: 259960 + 670 = 260630
Step 390: 260630 + 670 = 261300
Step 391: 261300 + 670 = 261970
Step 392: 261970 + 670 = 262640
Step 393: 262640 + 670 = 263310
Step 394: 263310 + 670 = 263980
Step 395: 263980 + 670 = 264650
Step 396: 264650 + 670 = 265320
Step 397: 265320 + 670 = 265990
Step 398: 265990 + 670 = 266660
Step 399: 266660 + 670 = 267330
Step 400: 267330 + 670 = 268000
Step 401: 268000 + 670 = 268670
Step 402: 268670 + 670 = 269340
Step 403: 269340 + 670 = 270010
Step 404: 270010 + 670 = 270680
Step 405: 270680 + 670 = 271350
Step 406: 271350 + 670 = 272020
Step 407: 272020 + 670 = 272690
Step 408: 272690 + 670 = 273360
Step 409: 273360 + 670 = 274030
Step 410: 274030 + 670 = 274700
Step 411: 274700 + 670 = 275370
Step 412: 275370 + 670 = 276040
Step 413: 276040 + 670 = 276710
Step 414: 276710 + 670 = 277380
Step 415: 277380 + 670 = 278050
Step 416: 278050 + 670 = 278720
Step 417: 278720 + 670 = 279390
Step 418: 279390 + 670 = 280060
Step 419: 280060 + 670 = 280730
Step 420: 280730 + 670 = 281400
Step 421: 281400 + 670 = 282070
Step 422: 282070 + 670 = 282740
Step 423: 282740 + 670 = 283410
Step 424: 283410 + 670 = 284080
Step 425: 284080 + 670 = 284750

So, 670*425 = 284750